How to Notate Special Events in Chess
Algebraic chess notation is universally understood in the chess world because it doesn't rely on a particular language. With algebraic notation, each square is indicated by a file letter (a–h, indicating which column it's in) and a rank (1–8, indicating the row). Each piece except the pawn is represented with a capital letter. With this information, you can indicate the movement of any piece on the chess board with just a few characters.
Some chess moves, however, involve more than just moving a piece. These moves are notated in special ways.
Indicating captures in chess
To indicate a capture with chess notation, you use an x along with the name of the square where the capture is made. Imagine a game that begins with white moving a pawn to e4, followed by a black pawn move to e5. White then moves another pawn to d4. The notation looks like this:
d4White and black face off, and a white pawn steps out to d4.
Black can capture the white pawn on d4 with its pawn. This capture is written as follows, and the following figure illustrates it.
d4 exd (or 2. ...exd4, which is more precise)
Either notation is correct, because the black pawn can only capture on that one square on the d-file. You may also have noticed that only the file (e), not the file-rank (e5), of the attacking pawn is given. You can leave off the rank because black has just one pawn on this e-file, so the rank is understood.
Noting a castle in chess
Castling is the only time in chess when the king can move more than one square. You may castle on the kingside or on the queenside, but the rule is the same: The king moves two unoccupied squares to the right or left, and the rook slides around the king to occupy the adjacent square on the king's opposite side.
The notation for castling on the kingside is 0-0; the notation for castling on the queenside is 0-0-0. When white castles on the kingside, then, it is written like this:
0-0White castles on the kingside.
Recording a pawn promotion
You may play lots of games without ever promoting a pawn, but if you do end up moving a pawn all the way across the board, you’ll need to be able to write the move down correctly.
You notate the promotion of a pawn by adding the piece designation to the move. For example, if on your 40th move you play your pawn to the eighth rank on the b-file and promote it to a queen, you write 40. b8Q. If you promote to a bishop, you write 40. b8B.
Accounting for ambiguities in chess notation
Sometimes, two pieces can capture on, or move to, the same square. (This situation doesn’t happen very often, but when it does, the pesky knights are usually the culprits.) In the following figure, two knights can move to the same square, d2. Chess players solve that potential dilemma by adding the file to the piece designation, as in N/bd2. This notation means that the knight standing on the b-file is the one that moves to d2.
So what do you write if two knights on the b-file can move to d2, as in the next figure? To indicate which knight moves in that case, write the entire designation of the originating square: N/b3d2. Or for clarity’s sake, you can add a hyphen: N/b3-d2. This notation means that the knight on b3 moves to d2.